I've currently got my Opteron 170 at 2.7GHz (270 x 10) with the RAM on a DDR333 divider which brings it down to 225MHz. Now that's getting to it's limits as it's only rated as DDR400 so I wanted to have a bit of a re-arrange.

I tried setting the multiplier to x9 and so upped the FSB to 312 to get a nice 2.8GHz. I then set the RAM divider to DDR266 as this would take it down to 200MHz.

BIOS loads... Windows logo... blue screen.

I figured it couldn't be the CPU so I tried running the DDR200 divider and hey presto I hit the Windows desktop.

Does the AN8 Ultra have any known issues with certain RAM dividers?